1. Field of the Invention
The present invention relates to a ratchet tool, and more particularly to a ratchet tool having a rounded or smooth pawl engaging mechanism for allowing pawls to be smoothly actuated to engage with a gear by a control ferrule.
2. Description of the Prior Art
Various kinds of typical ratchet tools or ratchet mechanisms have been developed and each comprises a block or cartridge attached to a handle, a rod or gear rotatably engaged into the block or cartridge for coupling to a driving shank, and two pawls slidably engaged into the block or cartridge for being biased to engage with the rod or gear, in order to control the driving direction of the driving shank.
For example, U.S. Pat. No. 5,523,093 to Lee, and U.S. Pat. No. 5,522,081 to Lin disclose two of the typical ratchet tools or ratchet mechanisms each also comprising a driving shank for coupling to a base cartridge of the handle selectively with two pawls, and the pawls each includes a number of teeth for engaging with the teeth of the rod or gear or driving shank, in order to determine or to control the driving direction of the driving shank relative to the handle.
Normally, a control ferrule is rotatably attached onto the handle or the base cartridge, and engaged with the pawls, for selectively urging or forcing the pawls to engage with the teeth of the rod or gear or driving shank respectively.
However, the control ferrule is frictionally engaged with the pawls and a frictional force may be occurred or generated between the pawls and the control ferrule, such that the pawls may not be easily and smoothly forced and moved to engage with the teeth of the rod or gear or driving shank by the control ferrule, and such that rubbing or wearing problems may be occurred or generated between the pawls and the control ferrule.
U.S. Pat. No. 6,227,077 to Chiang, and U.S. Pat. No. 6,250,183 to Chiang disclose two further typical ratchet tools or ratchet mechanisms each also comprising a driving shank coupling to a base cartridge of the handle selectively with two pawls, and the pawls each includes a number of teeth for engaging with the teeth of the rod or gear or driving shank, in order to control the driving direction of the driving shank relative to the handle.
Similarly, a control ferrule is also required to be rotatably attached or engaged onto the handle or the base cartridge, and engaged with the pawls, for selectively urging or forcing the pawls to engage with the teeth of the rod or gear or driving shank respectively.
However, similarly, the control ferrule is also frictionally engaged with the pawls, such that the pawls may not be easily and smoothly forced and moved to engage with the teeth of the rod or gear or driving shank by the control ferrule, and such that rubbing or wearing problems may be occurred or generated between the pawls and the control ferrule.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional ratchet tools.